In recent years, because of the exponential increase in the cost fine processing technology for digital computers, analog computers have been suggested. Where a stored conventional digital technology must be used, its is necessary to apply both digital processing and analog processing.
In a field of filters, circuits using analog data and circuits using digital data are known.
Analog circuits provide the benifits of; high speed processing, small size and low price. On the other hand, digital circuits provide the benifits of: easy change of configuration, and arrangement of but have the disadvantages of accuracy, large size and high cost.
The inventors of the present invention have filed an application for analog filter circuit of including a plurality of multiplication circuits connected in parrallel to input data. A plurality of multipliers are stored in a memory to which the multipliers are inputted through one bit pin of a filter device. This package design is advantageous for minimizing the size of device. To inspect the function of the memory, however, the test pins increase device size.